This project is a longitudinal study of two hundred Caucasian families and their children who represent some of the variant family styles in which American children are growing up: communes or living groups; social contract couples (not legally married); and single mothers. A two-parent married nuclear family group serves as a comparison sample. The study documents the family environments and child-rearing practices, and examines the developmental implications for the children. Extensive interviewing, psychological testing and naturalistic observations in the home environment have been the main methods of following the children from birth through their first 5 years of life. Outcome variables of interest include emotional and social development, gender identity, school readiness measures, cognitive development and related measures. Proposed work during the coming year includes the following: (1) Completion of home observations when each child reaches 4-1/2 years of age; (2) Psychological assessment and socioemotional assessment of the children entering first grade during 1980; (4) Continuation of statistical analyses, with special attention to continuities and discontinuities in parent behaviors and attitudes, and child development over time. Mental health and applied research implications relate to the ability of children growing up in non-nuclear traditional families to adjust to educational, medical, and social mainstream institutions; the adjustment, in turn, of institutional and service-related mental health care services to these new emerging family lifestyles; and implications of these family styles and the developmnt of children in them for American family policy.